German RepRap Introduces New Polyurethane Material, Developed with ebalta Kunststoff for Liquid Additive Manufacturing Process

Typically when we hear about polyurethane (PU) material, it’s being utilized as a foam for things like mattresses, upholstery, insulation, or even mixed with shaving cream to 3D print a statue of Sir Wilfrid Laurier. But this week, top German FFF 3D printer manufacturer German RepRap and ebalta Kunststoff, which manufactures polyurethane and epoxy resins, have introduced their new customizable PU-based material, which is not a foam, for German RepRap’s Liquid Additive Manufacturing (LAM) process, first introduced at formnext in November; 3DPrint.com had a chance to see the company’s LAM process in action at RAPID 2017 as well.

RAPID 2017

Floridan Bautz, the Managing Director of German RepRap, said at RAPID in May, “We can see a fundamental rethinking process in the minds of the entrepreneurs. More and more it is considered whether additive production can be used instead of the injection molding and milling processes. The new Liquid Additive Manufacturing (LAM) Technology is a revolution in 3D printing and will strongly influence this rethinking in a positive sense. Actually we can say it is the beginning of a new age, since there has been no comparable technology anywhere in the world.”

The flexible new PU plastic was officially introduced in June at the PSE Europe 2017 show in Munich, and spectators at the event got to see a live demonstration of a German RepRap LAM printer processing the material. This live demo was the first in the world that showcased how liquid materials, such as silicone and the new PU material, can be processed using LAM 3D printers.

LAM 3D printing is similar to the FDM technique, where each layer is cross-linked through thermal cure to create complex parts. The parts feature mechanical properties not too different from injection molded parts, but the geometries are far more complex.

This revolutionary new material, being touted as liquid silicone rubber, offers customizable properties, which make it able to work with a range of applications and requirements. Because of chemical crosslinking, the material has istropic mechanical properties once it’s been printed. This is a big deal – for the very first time, a PU material is able to be processed in its liquid state, which completely eliminates the need for the melting process. German RepRap and ebalta developed the material so it was able to create several different properties, from hard to soft.

While the structures created from this material during the LAM process are similar to ones created from an FFF process, the printed parts are very complex, and would be nearly impossible to create using injection molding, though their mechanical properties are similar. Polyurethane materials are well-suited to special applications, including those which need high wear-resistance, thanks to their unique properties, including flame resistance and strength.

In addition, when the material is processed at room temperature, the printing process is more energy-efficient, and causes a low material shrinkage between 1 and 2%, which means that thermal warping and detachment from the print bed are no longer an issue. But thanks to German RepRap’s LAM process, and this new PU material, new applications are available, such as functional models for consumer goods and prototype construction.

Discuss in the German RepRap forum at 3DPB.com.

[Images courtesy of German RepRap]